The invention relates to an apparatus for making two truly parallel cuts in a piece of sheet material or the like at the same time. Conventionally, especially in the sheet metal cutting trade, in order to make parallel cuts in a sheet one cut must be made, and then the other cut only after the first cut is made and the sheet realigned. It is difficult to make the second cut parallel to the first cut, especially when the cuts are arcuate, and expensive accessory means often must be employed for facilitating the making of the second parallel cut, or very skilled craftsmen must be employed. Also, the process is relatively time consuming since two separate aligning and cutting procedures must be followed.
According to the apparatus of the present invention, the above-mentioned problems associated with the prior art have been eliminated to a large extent. When two parallel cuts are to be made, they may be made at the same time, and the making of one cut insures that the other cut is truly parallel thereto. According to the invention, a band saw and a saber saw are provided, both extending through a working surface table top for movement in parallel vertical planes when making cuts in sheet material or the like. The leading edges of both saw blades are aligned so that a workpiece will encounter them at substantially the same time, and power means are provided for operating them at the same time. The saber saw is adjustable in a horizontal plane with respect to the band saw so that any desired width of material may be cut. Also, the saber saw blade is mounted so that it can pivot from its vertical, cutting position, to a substantially horizontal position below the table top, whereby the band saw can be used alone. While there have been some prior art proposals to provide more than one saw associated with a working surface -- see U.S. Pat. Nos. 123,211 and 2,815,775, for example, such proposals have in general required that only one saw be operable at a time, and thus two parallel cuts could not be made at the same time. Also, such prior art saws have not been of the type that are conducive to making parallel cuts that are arcuate -- as opposed to the present invention wherein the band saw and saber saw blades have substantially the same effective cutting action, and are well suited to work with each other to make parallel arcuate cuts -- and such prior art saws have not been adjustable with respect to each other to allow for cutting sheet sections of different widths from a sheet of material.
According to the present invention any suitable means may be provided for moving the saber saw with respect to the band saw for adjusting the distance between the parallel cuts to be made thereby and such means may include a slot disposed in the table top for guiding the linear movement of the saber saw, a rotatable screw rod disposed under the table, and means associated with the saber saw for surrounding the screw rod and transforming the rotary movement thereof to linear movement of the saber saw. The saber saw pivoting means may include a shaft for mounting the saber saw for pivoting movement, a gear member disposed on the end of the shaft and cooperating with a worm gear, and a keyed shaft for supporting the worm gear for rotation while still allowing relative linear movement of the worm gear depending upon the position to which the saber saw is moved by the means for adjusting the distance between it and the band saw. Also, a workpiece resting means may be associated with both the band saw and saber saw for particular use therewith when sheet metal is to be cut, each workpiece resting means providing a surface that is parallel to and elevated above, the table top. The workpiece resting means associated with the saber saw can also provide a guiding function for linear movement of the saber saw, and an opening can be provided therein for receipt of a pivot post to allow a workpiece to be pivoted thereabout to have an arcuate cut made therein by the band saw when the saber saw blade is in its unoperative, horizontal position.
The primary object of the present invention is to provide practical apparatus for making two truly parallel cuts spaced any distance and either arcuate or straight -- in sheet material or the like. This and other objects of the invention will become clear from an inspection of the detailed description of the invention, and from the appended claims.